This invention relates to an apparatus for slicing or shearing roof membranes to prepare them for removal. In this application, it is understood that the terms slicing and shearing have the same meaning in the context of preparing roofing materials for removal.
Built-up commercial roofing material, which typically must be removed prior to installation of a new roof, often includes asbestos, which has been recognized as a potentially hazardous material requiring care in its removal. To protect workers, current regulatory rules require that strict precautions must be taken in removing asbestos roofing material. These regulations are most stringent if asbestos fibers are emitted during removal of a roof of this type. Such regulations mandate that protective equipment be used by workers if fiber counts exceed certain levels, and also mandate extra steps in the removal process; steps not required if fiber levels o are kept low. As can be appreciated, compliance with such regulations significantly increases labor and equipment costs, making this type of work relatively expensive and time-consuming.
In the past, it has been known to utilize a rotary saw to cut the roofing material into sections, which are then removed from the roof. However, use of a saw results in generation of a substantial amount of dust and debris. When asbestos-containing roofing material is cut with a rotary saw, it then becomes necessary to comply with the most stringent regulations governing asbestos roof removal as set forth above.
Accordingly, it is an object of the present invention to provide an apparatus to prepare roofing material for removal, particularly roofing material including asbestos, which results in generation of no dust or debris which otherwise would trigger operation of the most restrictive asbestos removal regulations. It is a further object of the invention to provide a method of preparation for roof removal which is relatively simple and efficient, enabling an operator to lower the time and expense involved in roofing material removal.
In accordance with one aspect of the invention, a powered tool for slicing or shearing built-up roofing is operated on the roofing material to slice or shear the roofing material into sections, which are then removed. Slicing or shearing of the roofing material eliminates generation of dust or other particles into the air, thus avoiding the effect of the most burdensome regulations governing removal of asbestos roofing material. The powered tool includes a hand-operated prime mover including a power source, one or more wheels operatively connected to the power source, and a manual control for selectively transmitting power to the wheels from the power source for moving the prime mover along the roof. A slicing mechanism is mounted to the prime mover, including a blade and an arrangement for mounting the blade to the slicing mechanism. A raising and lowering assembly is interconnected with the prime mover for selectively raising the blade above the roofing material and selectively lowering the blade into the roofing material. The mounting arrangement for mounting the blade to the slicing mechanism includes a frame connected to the prime mover, and the blade is preferably rigidly fixed to the frame. The frame may be fixed in any location on the prime mover, and representatively may be fixed to its rearward end. The raising and lowering assembly functions to move the rearward end of the prime mover upwardly and downwardly relative to the roofing material for raising and lowering the blade relative to the roofing material. The raising and lowering assembly is interconnected with the frame, and includes a support member such as a wheel or skid, and a bracket assembly to which the support member is connected. The bracket assembly is pivotably mounted to the frame, and a manually operable handle is interconnected with the bracket assembly for controlling the angular position of the bracket assembly and the support member relative to the frame to thereby control the vertical position of the prime mover, and thereby the cutting blade, relative to the roof. A retainer arrangement is interposed between the bracket assembly and the frame for selectively maintaining the support member in a lower position in which the blade is raised above the roofing material. An adjustable stop mechanism is interposed between the frame and the bracket assembly for adjusting the upper position of the support member relative to the frame, to thereby control the depth of penetration of the blade into the roofing material when the blade is lowered into the roofing material by movement of the bracket assembly and support member between its lower and upper positions.
The invention further contemplates a method of preparing roofing material for removal, substantially in accordance with the foregoing summary.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.